1. Field of the Invention
This invention relates to a focus detecting device used in still cameras, etc. and in particular, to the assembly adjusting mechanism thereof.
2. Related Backgound Art
A photo-taking light beam passing through a photo-taking lens is directed to a line sensor comprising a photoelectric conversion element, and the focus adjusted state of the photo-taking lens is generally detected on the basis of the output condition of the line sensor. The line sensor and a focus detecting optical system for directing the light beam to the line sensor are made into a unit, whereafter the unit is mounted on a camera body, whereby a camera is assembled.
At such time, bringing the optic axis of the photo-taking lens in the camera body into coincidence with the optic axis for detecting the focus in the focus detecting unit body is an important factor in enhancing the detection accuracy. This also holds true of the angle of inclination of the surface of the line sensor with respect to the optic axis.
An example in which adjustment of the inclination of the photoelectric conversion element is effected is proposed in U.S. application Ser. No. 740,492. Such proposition discloses the technique of ensuring the light-receiving surface of the line sensor to keep a desired angle with respect to the optic axis. This is because there is a problem that an attempt to adjust, for example, the lengthwise inclination of the line sensor with respect to the optic axis would leave the inclination of the line sensor in a direction perpendicular thereto. In Japanese Laid-Open Patent Application No. 39612/1985, the inclination of the unit body is adjusted to thereby accomplish pupil alignment adjustment. That is, the optic axis of the unit body is made to face the center of the pupil of the photo-taking lens. However, this does not always bring the photo-taking optic axis into coincidence with the optic axis of the unit body, and thus causes parallax.